1. Field of Invention
This invention relates to an automatic tire inflation system for automobiles. More specifically, it relates to a tire inflation system for heavy vehicles, such as trucks and vehicles carrying heavy equipment, in which the tire pressure may be automatically maintained at a level at which fuel consumption, tire wear and road deterioration are minimized.
2. Prior Art
During World War II, the United States military services developed a system for automatically inflating vehicle tires while in transit. This system is referred to as "Central Tire Inflation System." Its purpose was to allow the driver of the vehicle to inflate the vehicle's tires to a higher air pressure, or to lower the air pressure in the tires, to accommodate a variety of road conditions ranging from sandy beaches to dirt roads. Control of the vehicle tire air pressure is provided by an air pressure controller which can be manually adjusted in the cab of the vehicle by the driver. The system provides an air compressor, driven by the vehicle's engine, which is connected through the air pressure controller to the vehicle's front and rear tires. Rotary seal connections are provided at each wheel to allow the flow of air from the air supply to the tires while the vehicle is in motion and its wheels are rotating. Systems for regulating tire air pressure are disclosed in U.S. Pat. Nos. 4,313,483 and 4,431,043.
It is known that tire pressure has an effect on road traction, fuel economy, tire wear, and road deterioration at different vehicle speeds and accelerations, rear axle torque, and for different vehicle weights. However, no use has been made of these known relationships to minimize fuel consumption, tire wear, and road deterioration by automatic means. There is a need, therefore, of apparatus and methods for accomplishing these goals.